Passing java's status code to c++

[Karthik Veeramani]

I have a c++ wrapper over a java application, and c++ uses the jni library to launch a jvm, and invoke the main method of the application. I have a requirement that, when the java application exits, it has to pass the 'status code' to the wrapper somehow. By status code, I mean, "return 0" or "return 1" or something like that which we do in C's main function. But as the main method is void return type, I don't know how to handle this. Can someone help?

[Ernest Friedman-Hill]

You have a requirement that you have to do something with a value that doesn't exist? Well, as I see it, you've got a few options: you could make a value up (for example, always return 0); you could define and document a value (0 for normal return, -1 for RuntimeException, -2 for error, for example); or, and I know this is a crazy idea, you could talk to the customer about the requirement!
If you, as a developer, get a meaningless requirement, the only professional course of action is to try to get the requirement clarified.

[Dana Hanna]

You are looking for the method:
System.exit(<int value here> ;
The reason that main doesn't return anything is because the main exiting doesn't mean that the program is over. It could have launched other non-daemon threads that would continue execution.
Calling System.exit(int) will end all threads and send the exit code given back to the calling process.